what is (7k-3)(k2-2k+7)
( 7k - 3) ( k^2 - 2k + 7) =
7k ( k^2 - 2k + 7 ) = 7k^3 - 14k^2 + 49k
+ +
-3 ( k^2 - 2k + 7) = -3k^2 + 6k - 21
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7k^3 - 17k^2 + 55k - 21